Introduction
Early T cell precursor acute lymphoblastic leukemia (ETP ALL) is a relatively new, high-risk subgroup of acute lymphoblastic leukemia (ALL) characterized by unique immune-phenotype and disease biology. ETP ALL cells share similarities with hematopoietic stem cells and myeloid progenitor cells [1]. Immuno-phenotypically it is characterized by CD1a, CD8, CD5 (dim), and positivity for 1 or more stem cell or myeloid antigens [2]. As compared to patients with non ETP-ALL, these patients have lower rates of complete remission (73% vs 91%; P  = .03) and overall survival (OS)(20 months versus not reached, P  = .008). ETP ALL has been shown to be BCL 2 dependent and is sensitive to in vitro inhibition by BCL2 inhibitors [3]. Venetoclax is an orally bioavailable BCL 2 inhibitor approved for use in acute myeloid leukemia, chronic lymphocytic leukemia and multiple myeloma [4]. Response of relapsed refractory T cell ALL with venetoclax based therapy have been reported in literature. We present the treatment outcomes of 2 patients with ETP ALL treated with venetoclax.